1. Field of the Invention
The present invention relates generally to hearing aids and to methods of manufacturing hearing aids. The invention, more specifically relates to Behind-The-Ear (BTE) hearing aids and methods of preparing them. The invention, still more particularly, relates to custom-made BTE hearing aids.
2. The Prior Art
Behind-the-ear (BTE) hearing aids is a subgroup within the general group of hearing aids worn by the ear. Hearing aids supported entirely by the ear are normally divided into three classes: Behind-The-Ear (BTE) hearing aids, In-The-Ear (ITE) hearing aids and Completely-In-the-Canal (CIC) hearing aids. A BTE hearing aid is the largest type and basically incorporates a housing or a shell that is adapted for being placed partially above and partially behind the users outer ear (the pinna). The housing provides a platform and encapsulation for electronic and acoustic components, such as a battery, a microphone, and an amplifier. In some types, the housing also contains a miniature loudspeaker, in the hearing aid parlance usually referred to as a receiver, which connects to a tube for conveying the receiver output into the ear canal of the user. The tube ends in an earpiece that couples with the ear canal. The earpiece may comprise a soft standard plug or it may comprise a customized plug. In use the housing is placed behind the external ear, partially concealed. In some BTE's the housing extends into a hook that serves the purpose of resting the hearing aid housing. U.S. Pat. No. 6,228,020 shows a hearing aid with a faceplate and a shell customized to fit in the user's ear canal.
WO-98/47319 shows a hearing aid for arrangement in a user's ear canal and including a shell customized to the users ear canal, components and a faceplate.
DE-U-1784750 discloses a BTE hearing aid with an individually formed housing, which housing is molded by a method as is known from the field of dentistry, so as to fill the space between the pinna and the head of the user. In the housing there is a hearing aid connected to an ear piece by an air conduit. The disclosure gives no enablement regarding how to integrate hearing aid components into the housing.
AT patent 194933 discloses a BTE hearing aid, wherein the housing is provided with exterior plastic moldings adapted to improve the seat. The housing may be provided with an aperture for threading through a side bar of a pair of glasses.
BTE hearing aids offer space for large batteries, larger amplifiers, telecoils, dual microphones, push buttons and switches to change between various functions etc. Such features are difficult or impossible to implement in smaller types. BTE hearing aids also permit the arrangement of a microphone and a receiver with a mutual spacing that better permits controlling acoustic feedback from the receiver to the microphone. Some users may find BTE hearing aids more comfortable in wearing. Thus, many users find good reasons to prefer BTE hearing aids rather than ITE or CIC hearing aids.
The state of the art BTE hearing aid comprises a standard housing that is curved to suit the general contour of the cleft between a pinna (left or right) and the skull of a user. The top part of the housing normally extends into a projecting hook that incorporates a sound conduit and provides a grip around the top part of the cleft between pinna and skull.